Chrome Version       : 68.0.3422.0
OS Version: OS X 10.13.3

What steps will reproduce the problem?
1. chrome://flags/#force-ui-direction set to RTL
2. Edit a bookmark
3. Add folders until horizontal scrolling is necessary
4. Scroll horizontally using shift+wheel or trackpad

What is the expected result?

Scroll direction should be consistent with webcontents

What happens instead of that?

It's backwards.


Note I'm not sure if this also affects Windows/CrOS yet... maybe it does. But my trackpad isn't working there (or over RDP :/).